The effect of carbon content on the structure and photocatalytic activity of nano-Bi2WO6 powder

Carbon-doped nano-Bi2WO6 photocatalysts with different carbon contents were successfully prepared by a facile hydrothermal method at 433 K and characterized by XRD, BET, XPS, TEM, HR-TEM, SEM, EDX, photoluminescence (PL) and UV-vis spectroscopy. The photocatalytic activity of C-Bi2WO6 was evaluated from the analysis of the photodegradation of methylene blue (MB). The results show that the C-Si2WO6 photocatalysts exhibit an orthorhombic Bi2WO6 phase. With the increase of carbon content, the absorption intensity of C-Bi2WO6 samples increases in the 410-650 nm region and the absorption edge has a little shift to long wavelength. Compared with reference C-TiO2 or pure Bi2WO6,0.47% C-Bi2WO6 shows obviously higher UV and visible light photocatalytic activities. The remarkably enhanced photocatalytic activities can be mainly attributed to the fact that the proper carbon doped into nano-Si2WO6 increases its BET surface area, enhances the absorption in the 410-650 nm region, improves the separation efficiency of photogenerated electrons and holes, and enhances the formation rate of center dot OH on its surface. (C) 2013 Elsevier B.V. All rights reserved.